The field of this disclosure relates generally to systems and methods for data reading and/or image capture, and more particularly, to systems and methods for aiming and calibrating a data reader in a data reading system.
Data reading devices are used to read optical codes, acquire data, and capture a variety of images. Optical codes typically comprise a pattern of dark elements and light spaces. There are various types of optical codes, including one-dimensional codes, such as a Universal Product Code (“UPC”) and EAN/JAN codes, and stacked and two-dimensional codes, such as PDF417 and Maxicode codes.
Data reading devices are well known for reading UPC and other types of optical codes on packages, particularly in retail stores. One common data reader in such systems is an imaging reader that employs an imaging device or sensor array, such as a CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) device. Imaging readers can be configured to read both 1-D and 2-D optical codes, as well as other types of optical codes or symbols and images of other items. Though some imaging readers are capable of using ambient light illumination, an imaging reader typically utilizes a light source to illuminate the item being read to provide the required signal response in the imaging device. An imager-based reader utilizes a camera or imager to generate electronic image data. The image data, typically in digital form, is then processed to find and decode the optical code.
In some data reading systems, a top-down data reader is used to capture an image of a top surface of an item for decoding an optical code that may be present on that top surface. In such data reading systems, the top-down data reader's position may be permanently fixed at a preset height position, such as a factory setting or a user-defined setting. In such data reading systems with a fixed position for the top-down data reader, issues with aiming and calibration may not be problematic because the top-down data reader may be calibrated based on the fixed position. Since the top-down data reader's position is fixed or experiences only minimal movement, further calibration by the user is usually unnecessary.
However, data reading systems with fixed data readers have several disadvantages. For example, such systems may lack flexibility and cannot be easily adapted to fit a variety of workspace configurations. In addition, such systems are typically limited to processing items that do not exceed certain height dimensions based on the fixed height of the top-down data reader. A data reading system with a height adjustable and/or remotely mountable top-down data reader may address these limitations by providing a data reader that can be raised, lowered, or otherwise repositioned as desired. However, the present inventors have recognized that such height-adjustable and/or remotely mountable top-down data readers may have issues with aiming and calibration after adjustment. For instance, the top-down data reader may require calibration after some or all adjustments to ensure proper orientation and that the data reader has an acceptable depth of field to accurately capture the optical code or other target data. The present inventors have, therefore, determined that it would be desirable to provide a scanner or reading system with a movable/adjustable top-down data reader for maximizing flexibility, and a calibration subsystem for ensuring optimal performance of the top-down data reader.
Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.